I thought the whole point of hot waxing is that you just dunk it in the hot wax, give it a swirl, and whatever is on the surface goes to the bottom. What's on the bottom stays there. I can see giving the chain a wipe down with a rag, or even blowing some mild pressure compressed air on it to blow off surface debris but boiling water makes for one hot mess, but that's just me. I get it, it's your stuff and you're gonna do what you're gonna do regardless. So what's the point of asking for the forums thoughts ?
I'd use a propane torch(lightly) before I'd use boiling water. At least once to try it. When I used Squirt water based drip wax it tended to build up on the rings and cogs. The only way I found to remove it effectively was to soften the wax with careful use of a propane torch. I had one on hand, long unused, so I tried it. Then I could wipe it right off. White Lightning Clean ride petro based drip wax didn't build up and worked a little longer between applications.
There's no perfect lube for everyone all the time absolutely however as asking what's best is like asking what's the best method to fill a hole in the Titanic ?