Chloroform doesn't work like in the movies, it would be incredibly difficult to knock someone out with it. Same with head trauma. If someone hit someone else in the head with a bat they will probably either just get pissed off or if it's a bad enough concussion, have a seizure and/or pass out. And probably not for very long. And there's a chance they'd die from that alone if it's actually bad enough to render them unconscious.
Prostitutes are a bad choice, they are always on guard and if the individual were to make even the slightest wrong move they would not hesitate to kill or maim in self defense. All of them, with very few exceptions, carry knives and they are all a lot tougher than they look.
A drug addict homeless person would be easy target if they are going through withdrawals.
In a hypothetical situation in which an individual wished to perform such a terribly heinous act as to harm a fellow human being which I in no way shape or form condone, it would be easy to seduce a junkie into an empty home such as one that has been foreclosed, condemned, or just for rent, with the promise of drugs.
Heroin, for instance, would render the user semi-catatonic and in a euphoric daze in which they could be restrained.
There's a reason female sadists usually work with males if they do that sort of thing, the physical labor. The dead (no pun intended) weight of even a small adult woman is more than a lot of people could carry.
Women however have a distinct advantage in luring prey, for obvious reasons. If a woman offered a hitchhiker a ride, they'd probably say yes.
Just rambling but it's hard to find people who talk about this.
I look at this like a puzzle. Except from the perspective of someone that would want to make sure the pieces don't fit together and the killer is the picture that someone can make out when they fit just enough, or just the right pieces together.
I wanted to be a detective or PI for the longest time, but there's almost no crime here and cops (around my area) have thankless boring jobs. But I can tell you I'd probably be able to catch you from what you said.
Everyone has friends, or at least people that notice them. But we will assume it is at least a week before someone reports them missing. Your lack of burying the body would invite scavengers. Most likely you'd go to a place convenient but out of the way, since you're a city person you'd think of it as a secluded area, but it would be hunter or hiker territory, since other city people think like you do in this instance.
If you sought a "non hunting are" such as a nature refuge to make sure there weren't hunters around (or trail cameras, which I can guarantee you wouldn't see.) it would be probably be Park Ranger territory and they are vigilant and hard core individuals.
Since you don't have a lot of carrying strength, the distance from the mode of transportation to the execution area wouldn't be that large.
Assuming it would indeed, be a not uncommon hunting or hiking spot, human remains would raise an alarm within a week, possibly a month.
By that time tire tread would be too old follow, but that really depends on the weather.
The transportation you took, which would have to be a private vehicle, if you pushed it into a or lake/pond, it would probably be found, if you'd ever owned it, it would be linked to you. If you'd bought a random car with no title off of someone and not registered it, the person who did own it would be found and they would tell them at the very least, your description. If you dumped the vehicle far away in the water in a different state, you'd have to get a ride home and renting a car would leave tracks so that's not an option.
This is too long, but it was fun to speculate, I'll stop here because I know nobody will read this. I'll type the rest if anyone wants to know the other ways you could probably get caught that you don't realize.
Towns don't have CSI teams like television, but for something very obviously sadist like you want to do, it would attract the kind of attention that would get a CSI team like they have on television. If for no other reason than someone/team wanting to get famous from catching a murderer.