I've seen people joking about sucking on a slice of lime and having all the hairs plucked from their body(/s) so they write faster. Something like that can work, but also just writing nonsense, or leaving nothing else to do. That's where the typewriter is handy I suppose as you can sit with it...
Really been enjoying using my typewriter, it's loud and annoying but switching off and just writing is such a nice feeling! I've read it's great advice to work on a piece, and fix it later. Typewriters make that so good to do. Also the smell is wonderful. Would reccomend