Should I remove the spark plug from the cylinder that I think has a head gasket leak when I use K-Seal? You did it in one video but not in another. I am doing the treatment because I go through a fair amount of coolant and the last time I changed my plugs there was lots of deposits on one of them. No liquid in the cylinder that I know of but it’s possible. It’s a 1986 VW Vanagon with the stock a 2.1 L water boxer. I have new plugs and will check for deposits and liquid before putting the k-seal in but I don’t plan on changing the plugs until the next day or so.
Those head gasket "sealers" are temporary bandaids at best that might not work at all and might plug up your cooling system. The only way to really fix a leaking head gasket is to replace it. If doing that is not feasible Scotty has recommended the Bar's Leaks head gasket product.
Have you checked the cooling system for leaks before condemning the head gasket?
