To answer some of the questions:
- The washcloth is for the fermenter and bottling bucket (simple plastic buckets). I just feel better about the Star San being spread all over the surfaces using a washcloth rather than paper towels or spray bottle. Dumping Star San into it and rotating sounds very effective, but messy.
- The washcloth isn't for cleaning - just for smearing the Star San around on all the surfaces. It gives me confidence that the whole surface is coated.
- I really never had a thought about the washcloth being a breeding ground for microbes. I might change over to something else - I'll have to mull it over. I hate giving up the confidence that I have in Star San hitting every square inch and every crevice of the surface. Maybe try the microwave idea or something similar. Or maybe a large wad of paper towels to get a similar effect.
Lots of food for thought. Thanks.
If you can pick up the item, pouring in an amount of Starsan (even a cup/8oz worth) and swirling it around (put the lid on to get that coated too) IS effective and has zero risk of being defeated by something you're using to 'spread all over the surfaces'. A spray bottle, set to a mist pattern is just as effective. Using a pump sprayer makes it easier and doesn't decrease how effective it is.
IMO/IME areas where you're doing this won't care about a little Starsan getting on surfaces. Or, at least, it shouldn't. It's easy enough to clean up afterwards to become a null issue.
When I sanitize my kegs, I pour a quart (or two) into the keg, make sure it's spread EVERYWHERE (shake, roll, etc.) with the lid on and it pressurized. I then push at least some of the Starsan OUT of the keg via the liquid post. This ensures the inside of that dip tube is also sanitized. I can also create a jumper and send some through the gas post and tube as I want. This is especially easy if I'm taking care of more than one keg.
For my fermenters, I use CIP (Clean In Place) ball to cover the entire inside of the conical. I use a pump to do this and recirculate the solution for at least a minute or two.
NO towels are use when sanitizing any of my gear. At MOST, I use some paper towels (saturated in Starsan) to cover openings post the chilled wort going into a fermenter, or to cover the opening of the funnel I use to pour the yeast into the fermenter.
IF I was to ever want to use a towel to 'spread' sanitizing solution inside something, I'd autoclave it to ensure nothing is living in it before I consider using it. Since that's more work than it's worth, there's pretty much zero chance of me doing that.