 The band never regained its credibility after fans learned they had not played the instruments on their earlier records.Sales still continued to be profitable until the disastrous release of the movie "Head".Nesmith's last contractual Monkees commitment was a commercial for Kool-Aid and Nerf balls in April 1970 (fittingly, the spot ends with Nesmith frowning and saying, "Enerf's enerf!