Neil talks to Entertainment Tonight while recording a voiceover for a new educational short from Listerine.

As for “This is Your Mouth,” Neil says he decided to lend his voice to the eight-minute film for a number of reasons: “I have a niece and nephew, and so I like being able to do darker, kind of ‘Harold & Kumar,’ Barney Stinson kind of roles that are a little edgier, but I also like to maintain a presence in the demographic within sort of a more educational slant.”

He adds, “I grew up going to EPCOT Center and things, so I enjoy the ‘narration’ voice.”

ET Online have put up a nice piece on Monday’s 100th episode, including a video clip which interviews Neil and the rest of the cast.

“Barney Stinson has shagged many a type of Betty … many different professions and varieties, but he has never shagged a hot bartender,” Neil tells ET. “He has to sleep with her. She, in turn, refuses to date guys who wear suits, from a past relationship. And, so, he takes it upon himself to have to choose between her or suits.”

The musical tribute is part of the celebration of the 100th episode of the CBS series, which also guest stars Rachel Bilson and Tim Gunn, playing himself.

Don’t forget that you can catch Neil on Jimmy Kimmel tonight at 12.05am/11.05pm central, and the People’s Choice awards air tonight on CBS from 9/8c. Neil, Alyson and the show are all nominated.