Puffs of Blue Smoke

1993 merc GM 90,000 miles bought new serviced regular at dealer, This car sits often and has been driven slow and seldom(parents are old)I try to blow the soot out so to speak and recently I have noticed blue smoke for short periods of time. The car runs great no issues at all no oil use to amount to anything great power 4.6 , Is there any addditives that could help clean out the internals to clean up the valves etc. that would stop the smoke? Again this has just started and I need to get a grip on this. thanks

Blue smoke is burning oil. If your oil use is "no oil use to amount to anything " then don't worry about it.