ok i wouldn't rebuild your engine just yet....
have you check your valve covers/rocker covers/cam covers to make sure the gaskets aren't leaking... they could be leaking oil down and when you remove the spark plug the oil is just flooding them as you pull it out.. it may not necessarily be your rings....
check your valve covers first (get some high temperature silicon and lightly around the gaskets put a little film of silicon... not too much because you don't want it going inside the head.. or just buy some new gaskets and clean the surfaces of the head so no grime is on there)
clean all your plugs
does your car smoke? if it does when does it
morning white smoke is normal
what colour?
when you pull out your plugs and clean it all up when you start your car there will be huge plumes of smoke but they will clear
let me know how you get on so far and i will continue
good luck