Interesting, I only very recently learned I have actually been autistic, finally explaining the weirdness of my past three decades+, so I am not knowledgeable about what language might be preferrable. Self-stimulating behaviour? I can only speak for myself that I actually do like the term, to me, it has a nice sound, one of those words that, to me, feels good to repeat aloud to myself.
Mayo + Ketchup combined, the classic “Rot-Weis”-combo in Germany.
That or, preferrably, mayo + a good chilli sauce