The Volts, who won the toss and opted to bat, must be rueing that decision in the wake of their capitulation at Colin Maiden Park in Auckland.
After at one stage stumbling to 37 for 8, they staged something of a recovery through Mark Craig and Nick Beard, who scored 10 and 14 respectively, to avoid the ignominy of being dismissed for less than 50.
Neil Broom (10) was the only other Volts batsman to reach double figures.
McClenaghan carded the fourth-best bowling figures for an Aucklander in domestic first-class matches and was ably abetted by wicketkeeper Gareth Hopkins, who pouched six catches off the bowler to equal the record he holds jointly with Reece Young.
Otago's record low is 34, scored against Wellington at Carisbrook in 1956-57.
In other matches starting today, Northern were 154-4 against Wellington in the capital early in the second session, while at Saxton Oval in Nelson Canterbury were 139-2 against Central.