I’ve had success with just dish soap - it makes blockages “slide” more easily.
In the last flatshare I lived, I had a particularly annoying combination of a slow toilet and a flatmate incapable of solving any blockages. Whenever I’d see that, I’d go “fuck this”, squirt a silly amount of Fairy in the bowl (I’m talking like 100 ml at least) and usually the blockage would resolve itself overnight.
I once had the great idea of drinking a litre of beetroot juice, which I had read is amazing for sports recovery because of something something helping blood carrying more oxygen or something like that.
Instant diarrhea, and on top of it, beetroot tinted it looked just like blood, so up until I realised what was going on and the fact that it actually wasn’t blood, that was a scary experience.
I don’t know whether beetroot is known to cause diarrhea or it was just my body noping the juice out of it, but I have steered clear of beetroot juice ever since!