Hi there,
Yes, I use the 5 gallon paint strainer bags and I have not had any issues whatsoever. I keep three on hand just in case thoughI will brew a barleywine next weekend, 5 gallons, 1.115 OG! Should be a good one, will need to use 2 bags and 2 mash tuns.
Any problem with the bag being in contact with the bottom of the kettle and getting to hot while maintaining the mash temps?