Do liquid block sealers fix head gasket leaks?

if you do it the right way/drain and flush engine so its only water/take out t /stat-cover the radiator and install the water and sealer run till hot with the sealer in it/make sure it gets to hot/shut engine off/let ever thing set for a 1 hr period/ drain radiator and the block/let it sit overnight/install t stat/fill at t/stat until the coolant level is up to t/stat/close the system and start up and add coolant as nec to fill the rest of the engine/should not be much to top off if you did it right and them drive it/did a few and it worked/wont help in ford 3.8 engines as heads are warped