Years ago I found one of those things on the wall and caught it in a jar. One minute after I caught it, I saw another one in the hallway. I put that one in the same jar as well and thought, great here's a friend for the first one.
I left the jar on the kitchen table and went to have a shower. When I get back 10 minutes later, one of the spiders ate the other. Or to be more precise it half ate it and was in the process of finishing it off.
I put the jar with the spider in the garage. That spider survived in that sealed jar for 9 months! I would have said it was cruel to try and suffocate a spider but hey, I wasn't the one that just ate somebody