You catch them with your bare hands as they don’t bite and are not known to be toxic. In my days, they are always kept in match boxes and the only acceptable accommodation for champions will no doubt be matchboxes of the “King Kong” brand, some of you older guys might remember this (girls don’t play with spiders in my days and as far as I know still don’t). Then some leaves are put in to provide moisture and a “homely” environment for them to hide and to feed them, any small insect will do but first they are to be incapacitated by squishing them half dead. To train champion fighters, the practice was to feed them smaller specimens of the same species, in an attempt to ignite their cannibalistic behavior thus making them more aggressive, or so we think, it all sounds so “inhumane” now but that was how it was done.
To make them fight, all that is needed is to bring two males together and while facing each other, a sort of ritualistic dance occurs with opponents circling each other with the front legs/arms open up as if they are sizing each other up before taking any physical actions. After a brief moment, the fight begins with their front legs or arms (we thought it was their claws at the time) locking up against each other in a push and pull motion. The loser is the one that gives up and runs away. I have not come across fatalities during this fighting matches but I do see injuries being sustained when an arm seem to have gone missing after a while. Properly fed and kept, I had one champion that I manage to keep for more than a month, before it escape because I did not close the matchbox lid properly and I never had one that died on me due to old age most probably because they always managed to escape before that happen