I have an idea on how to beat the towers
You need a team of honedge base and put exp.locks on them this works why you may aske well here's the answers to your question
Honedge can't be touched by toxic and hyper beam
Grass is not very effective to it
Surf is your main problem so carry sitrus berries if you have no sitrus berries then bring Oran's they will work to.
Hope this helped

hey! that's the same as i do anyways...this well help others as well

Is this idea for every tower or a specific tower?
Cause i want to start with the towers to

It works for the reward ones and the blissey