Valve cleaning without disassembling cylinder head

To know where compression is escaped, dry and humid compression should be taken. The procedure is like this:
1 Take the compression of the CIL. and write it down. (which is what they did)
2 Then a lot of oil is made in the cylinder and it is taken again, one by one and is noted.
Results: If the readings rise with oil more than 20% that means that the hoops or rings are spent, if you rise barely between 5 and 10% the problem is if in the valves.
There is no product that repairs those wear. They can hide it a few km, but the material that is no longer for wear reconstructs it.