What about Block + Toxic for trapping things besides pex?Block is better. You run Block + Spite to trap opposing Toxapex and other bulky Pokemon that cannot pivot out or break Toxapex. Infestation does very little due to the turn limit and passive nature of Toxapex, thus meaning it cannot kill the Pokemon within the limited amount of turns.
Block + Spite + Recover + Scald or Knock Off is the main viable trapping Toxapex.