Really Bad Bedbugs - Remove walls to do heat treatment?

[Brie Schmidt]

So we have had a serious bed bug situation for awhile now because these tenants would not follow protocol.  Now the building has been vacant for a few weeks and we did the spray but they are still there.  The treatment suggested by the property manager is to remove the drywall and do a heat treatment, which sounds a little overboard.  I have called a few bed bug companies and none have heard of removing the drywall to get rid of them.

Anyone done the heat treatment and still had an issue?

Would removing the drywall for an extra few thousand dollars make a difference?