Typically if a female doesn't scent up the tub fairly soon after the male enters there will be no courting going on during that visit.
This may not be every case but 90% of the time "in my experience" if they sit side by side for 24 hours they aren't going to be doing anything "wild" even if you let them sit 3-4 days together.

Low pressure systems moving in seem to help put them in the mood and placing males in with freshly shed females also seems to help some and I've used sheds before from other males with limited success, but I can't say for certain it was the reason the pair locked.

I figure if a male is just going to sitting in a tub curled up with a female on the other side of the tub he may as well be with a different female or resting in his own tub.