I believe that clip above is from around '93 (it is, it says so in the title, duh), so could be before he started using the DHP-55, but he apparently
did use it on Today....
Digitech DHP-55 Five Part Digital Harmony Processor.
Used by Billy Corgan on the 1995-1997 Mellon Collie and the Infinite Sadness album and tour. The unit includes Billy Corgan's settings for the following songs: Hummer, Cherub Rock, Drown, Soma, Rocket, and
Today. The unit has been kept in a smoke-free studio environment. No cables or manuals are included. A certificate of authenticity will be included. Unit is sold "as is".