If it's just the plug on the oil filter housing/cooler near the factory oil psi sending unit (aka: dummy switch), then yes - you can apply a small amount of teflon tape/plumber's putty to seal it up.
However, if the gaskets within the actual oil cooler assembly are leaking, then no - it will not be a permanent solution. The first step for a leaking oil cooler assembly is to usually re-tighetn the 1/2" hex/allen bolt where the oil filter screws into (once you remove the oil filter and peer inside of it, it will make sense). Tightening this rather large hex/allen bolt resolves the vast majority of leaking "cobra oil cooler" complaints.
G'luck.