The only McCulkin I have found in my years of research was a lady golf pro in Australia. I believe her name was Janet. Last name McCulkin.
I have found several variations of the "Culkin" name in my research in Ireland. I believe the beginning of my line was:
Source: Natl Library of Ireland, Dublin.
Richard McQuilkin 1642 Hearth Money Rolls,
Farranmacfarrall Townland, Co Sligo, Ire
Griffith's Valuation in the 1840's and 1850's listed all of my family members as Quilkin i.e. dropped the "Mc".
Other versions were Culkeen, Kulkin, Kulken and finally Culkin in the 1901 and 1911 Census's.
When I hear my cousin John Culkin at the "Culkin Emigration Museum" in Cannaghanally Townland pronounce "Culkin" it is fast and sounds like "Quilkin".
All of my relatives in the US and Australia are spelled Culkin.
Further back you find the Staunton name as indicated.
But from 1642 on the above is what I have found.
Tis all I know about "Culkin".