How many times triple bagels occured at slams in the open era?
6-0 6-0 6-0 - 5 times:
N.Spear def. D.Contet (Roland Garros 1968)
S.Edberg def. S.Eriksson (Wimbledon 1986)
K.Novacek def. E.Bengoechea (Roland Garros 1987)
I.Lendl def. B.Moir (US Open 1987)
S.Bruguera def. T.Champion (Roland Garros 1993)
Were there any instances of quadruple or quintuple bagels? (where the final score is obviously 3-1 or 3-2)
It has never happened in 40 years.