That is the stuff most of us use-there is also a type that is thicker and not as rigid-which is what I used this year, having had good results with it before-I will know in a day or two how well it worked in this once-every-30-years cold...
Mr mm is a big fan of it and as we do all out own work on our house, I’ve insulated my share of pipes with it.
Along with insulating the walls. That’s actually kind of fun and the rock wool is great to work with. An old bread knife is perfect for cutting it.