You read it here first, folks. After months of searching, CitySleuth has found the location of the Bellicec Mud Baths. The only online reference he had dug up was "somewhere on Clement Street," which turns out to be close but not the case.
... and Now, the bathhouse scenes were filmed at 5499 California Street at 17th Avenue in the Outer Richmond (map). Previously the L & E Market, it had been vacant for a couple of years before director Kaufman built a realistic movie set inside the store. The site has since 1998 been a children’s dance studio, the home of Miss Tilly's Ballet and Theater Arts.
Then ... Jack walks between two rows of massage booths towards the mud baths in the rear.
Then ... He begins to feel very tired and hardly notices the customers soaking in the baths.
... and Now, the dance studio has since been foreshortened by a new rear wall. If the set were there now the massage booths would be on this side of the new wall; the mud baths would be behind it.
Here’s the 17th Avenue side of the building in 2008, similar to how it was when the movie was filmed, compared with the building today. New apartments have been built next door encroaching into the 5499 California space and onto its roof. The dotted red lines indicate the position of the dance studio’s interior back wall Then and Now.
Jack lies down for a nap. The movie’s undercurrent of mystery is suddenly jarred into reality when Nancy comes looking for him. She screams in terror when, in one of the massage booths, she finds a hairy, slimed half-formed creature with Jack’s facial features. They don’t know it yet but his body is close to being replaced by a look-alike alien.
Then ... She finds Jack and wakes him up, unwittingly thwarting the body snatch. They call Matthew; as Nancy lets him in, the panning camera reveals two neon ‘BATHS’ signs, one in each of the store’s two front windows on either side of the central doorway (but note that the one on the right behind Matthew was not lit up during this scene - either an oversight or a setup problem).
... and Now, the entrance, previously with a double door, now has a single one.
When Matthew sees the body he has a dread feeling that Elizabeth, back at her home, may also be at risk. He finds her there asleep and carries her out, on the way passing another creature, this one with the features of Elizabeth. For the second time a body snatching takeover has been narrowly averted.
Then ... Kibner joins them all at the mud baths but Jack’s look-alike has vanished. This shot in the reception area with the front entrance on the right helped narrow CitySleuth’s search for the location because the windows beyond them meant that it had to be on a street corner.
... and Now, frosted glass on those same windows provide privacy from passersby.
Then ... An exterior scene filmed in front of the baths revealed more visual clues to the location: the wall detail at the corner behind Matthew, a kerbside power pole to the left and a curved arch at upper far left. The neon sign which was dark earlier (five images above) is turned on here. (The matching sign in the other window would be above Nancy’s head but is obscured by the car).
... and Now, the power pole is still there and the corner wall detail is the same. From here, trees block the view at upper far left of the adjacent space’s window arches corresponding to the curved detail above.