I book in outcall, so its MY hotel room, therefore the girl leave always before me. I never come in the condom, altough i know there is probably pre-cum or whatever, but i always just put it in the trash... I usually also leave beer caps, chips sac, other food stuff, and sometimes the trash is even full. I just wrap the sac everytime. Honestly they would got to be really weird people to open up the garbage sac to get one of my used condom... lol. Most of the time its an aged little women from another nationality, im pretty sure im safe it goes directly in the trash.
As for COPs... i book at hotels wich are not considered "prostitute motels" so hardly any chance to see them go there, and if they do... what happen in my room is my business... honestly what could they do really.
I tough John a couple time about my DNA in hotel rooms, and how if somebody really wanted to cause you trouble could, but at that point they use my hair on the pillow, or sometimes they remain in the bathub drain, and well.. so much posibility its north worth the paranoia.