I like to run scarf swampert on vgc since it has very good attack and with scarf it outspeeds very many Pokemon, but should I choose liquidation or waterfall?
Dont use scarf Swampert it’s outclassed by Scarf Basc.
If you insist on using scarf swampert for some strange reason I’d recommend liquidation as it allows you to do more damage to especially into Inciniroar allowing you to get the Pokemon into a range where you can guarantee the Ko with swampert or with another Pokemon. In general besides Rock slide and air Slash dont use flinch moves as they are inconsistent and there are typically more powerful alternatives.
-Source: Experience
Waterfall. Waterfall and liquadation both have a secondary effect and both being a 20% chance. Liquidations is defence drop (-1) while waterfalls is flinching. Flinching is better. But waterfall have 5 less base power. (Which doesn't really matter...)
WATERFALLLLLLLlll...