Great Vid, AHC. ((Hehe, same initials as Albert Health Care :))
I'm not sure if I would suggest a sealer. Air needs to circulate in order for the thrush to heal and the sealer would block air flow right? I've never dealth with thrush, but did take the time to learn alot about it since our springs can get pretty nasty wet here.
Remember that a call to your vet is always free, as is a google search. Of course you don't want to call you vet for EVERYTHING, but if you are in serious doubt then go ahead and call.