It's almost impossible to criticise this film in any conventional manner, Because most of the criticisms that you could level at it are the things it sets out to achieve.
If this were any other film you might complain that it's just as many offensive things as possible strung together; But that is entirely the point of the movie, in fact it was billed as "An exercise in poor taste". Even the terrible overacting seems to be a directorial choice, tailored to the scrip's constant use of hyperbole.
Unfortunately, just because something is deliberate, doesn't make it good, especially as the movie also, quite unintentionally, commits the cardinal sin, the one thing that really is unforgivable in a movie; for much if its runtime, it's dull.
Repulse me, shock me, make me hate you for killing a chicken just to make a movie, but by all that's unholy, please, do not bore me!
The plot, such as it is, is that (drag star) Devine has been named "filthiest person alive" and, due to the attention this brings, gone into hiding with her son, Crackers, her mentally ill egg-obsessed mother, Edith, and her traveling companion, Cotton.
Meanwhile Connie and Raymond Marbles, a couple who kidnap women, impregnate them, sell the babies to lesbian couples, and then loan the money to drugs pushers who operate in elementary schools (!) feel that they are more worthy of the "filthiest people alive" moniker, and set out to destroy Divine.
But really none of that is relevant, it's all an excuse for scenes such as toe sucking, a rape scene involving Crackers, his date and a chicken (the chicken ends up dead, but thankfully still a virgin), a "singing" asshole (a guy who can dilate his anal sphincter at will 'miming'), cannibalism , and the most un-erotic act of felacio you've ever seen; an obese man, playing a woman, sucking the flaccid cock of a man playing her son, punctuated with dialogue like "I want to give you a gift only a living mother can give" and "I want to receive it as a loving son should".
The highlight of the movie, is Edith Massy, Playing Devine's mentally changed, Egg obsessed, playpen dwelling, mother. At times she is so convincing that it gets uncomfortable to watch... If feels like they must be exploiting a genuinely disabled woman*
Finally, when the movie proper is over, there's one final thing; a non-sequitur that's one of the most famous scenes in cult / endurance cinema. I'm almost loathed to say what it is, but at the end if the day, I you're the type of person who's going to seek out an imported copy of a 70's gross-out film you probably already know about it.
Devine eats dig shit.
In one continuous shot, a little dog takes a dump, and Devine picks it up, pops it in her mouth and eats it; pausing only to flash the camera cinemas most literal shit-eating grin.
For my money though, even though it was fake, the shit eating in Saló is still worse, if only through frequency and volume. (Case in point; I described the Devine scene just with relative ease, but as soon as I began to recall Saló I say here dry-heaving at my keyboard).
I can see that, given the right crowd, the boring moments can probably be he heckled over and forgiven; indeed this movie did find some success on the midnight movies circuit; but at home, alone or with only a small group, it's a really bad movie.
I can't say 'avoid' because there's a lot if stuff that's worth seeing, if only because it's so unique, but unless a local cinema does a midnight revival screening, I can't come close to recommending it either.
I've said it many times, but I definitely like John Waters a LOT more than I like John Waters' movies; midnight screenings aside, give this a miss and track down the movie of his one man show "This Filthy World" instead - his Pink Flamingo anecdotes are wayyy more entertaining than the movie itself.
*I feel I should point out that, while certainly eccentric, Massey is not genuinely challenged in real life.