I'm pretty sure this works, but I'm double checking. Here's the scenario:

3 characters have been sent to the ko'd pile prior to the recovery phase. I have a Floronic Man (3 drop, Secret Society) in play. In my resource row I have a teamup that teams in Secret Society and Doom. I also have 3 The Enemy Within's (TEW). They trigger at the start of the recovery phase.

I respond to the trigger of the first one by KOing floronic man to bring back a card. TEW#1 resolves, I choose to return floronic man to play and RFG the other characters that went to the ko'd pile.

TEW#2 Goes on the chain. I respond by KO'ing floronic man and getting a card back. I return him to play with TEW#2.

TEW#3 Goes on the chain. I respond by KO'ing floronic man and getting a card back. I retun him to play with TEW#3. You get the idea.

Does this work? And if it does, I'm assuming I can do it with other KO effects as well?

Yes, that's fine. From the MHG FAQ:But to clarify the timing, each of the triggered effects goes onto the chain before you can play new effects. You're welcome to use an effect like Floronic Man's between each effect's resolution, it can just be important that they've all been placed on the chain before you get priority.