thats a personal choice. some here use it, some dont, and both have reported excellent results with both methods. i personally use a really thin layer of a gasket maker and the replacement gaskets called 'the right stuff' made by the same company that that makes the grey RTV sealant. never had any issues, and the stuff comes off relatively easy when you want it to. i just look at it as a little extra added insurance that it wont leak after i reassmeble. just dont want to go through removing it and doing it again, but if it's done properly you really shouldnt need any kind of sealant.