My understanding is that Starsan, as well as sanitising surfaces while still wet/foamy, creates an inhospitable environment for bacterial growth even when it has dried out.
So I:
- Circulate chemclean through my CFC for about 20 mins while I'm cleaning out my pumps, boil kettle, mash tun etc
- Rinse with a little hot water
- Suck out as much of what's left as possible with a wet vac, making sure to turn it over a few times to let water fall from one part of the coil to the next
- Spray Starsan in the top with the wet vac in the bottom port to help pull it all the way through. I then leave it to dry naturally, but if it never dries (I'll never know for sure!), my thinking is it's only starsan, not water
Then I just do the 10-min hot wort circulation at the end of the boil to re-sanitise.
I use pretty much same method for my Riptides as it saves having to tear them down and soak them as often. No problems so far. It seems like a lot of steps but it really isn't much work.