Isn't that what it says? You plug the send of one amp into the input, then plug the two outputs into the return.

It wouldn't matter if the amps were heads, combos, or whatever.
i use a setup similar to this. i actually include a 'dry' amp as well, so i actually use 3 amps.
punk isn't dead, it's always smelled that way.

"A perfection of means, and confusion of aims, seems to be our main problem."