I was given ActivHeal Hydrogel which worked well.
I did look to see if it was available, but I could only find bulk boxes with 200 tubes on Amazon.
All these are is a water based gel to keep the wound wet, which is how radiation burns are healed. A water based lube might work, except they mostly contain glycerin which contains sugar which might not be a good idea in a wound as it might promote bacterial or fungal growth.