http://www.stjosephsmen.com/letters/clownmass.htm
Google is my friend. It has been done before and here's the link. ECUSA isn't very original, this started in the Roman Catholic Church in the 70's.
http://www.stjosephsmen.com/letters/clownmass.htm
That explains some of the ads I see in National Review.
At least they had a reason. Joseph Grimaldi, the "King of Clowns" (1779-1837) is buried at what used to be St. James's Pentonville. Several circuses had their winter quarters nearby, and St. James's became the "Clowns' Church" because of the association with Grimaldi. Eventually (some time in the late 40s IIRC) they began to have a special Grimaldi Memorial Service. When that church was deconsecrated (and eventually wrecked out) the clowns moved the service to Holy Trinity Dalston.
They attend in full "motley and slap" (costume & makeup), and there's a memorial window to Grimaldi in a little corner chapel, with a banner that says "Here We Are Fools for Christ".
Joseph Grimaldi
All in all, it's typical English eccentricity and clubbiness, and I like it.
Silly priests thought they could get huge Broadway-style crowds to come for facepaint, clown Masses.