Is Revolution topical ointment necessary for an adult cat?

Hi, all. I understand that instructions on medications is prohibited. I am not seeking specific instructions, but rather hoping to get an unbiased opinion outside of my vet’s office, Banfield Pet Hospital within PetSmart.

I have a 2.5 year old neutered male Bengal. Each month, we give him Revolution’s topical ointment. It comes in a single dose tube and we squeeze it out onto his shoulder blades (so he can’t lick it off). I’m not sure if it’s the smell or if it stings his skin, but he absolutely hates it. Generally, he is not a sensitive cat and has a high threshold for what he will tolerate (he’s great at the vet, great with swallowing pills, very social, etc.). However, he becomes very fearful as soon as he sees the tube. After application, he has a pained look on his face (similar to you being pinched or smelling something bad) and usually darts under the bed for ~30 minutes, refusing to socialize. This same routine happens monthly with each application.

As a pet owner, it kills me. Revolution is also very expensive with each six pack costing $75+. I have asked my vet several times if we can stop the treatment because of (1) my cat’s reaction and (2) the cost. However, they insist that it is necessary for protection against heart worm, hookworms, etc., even though he is strictly an indoor cat with no health issues. No other cat owner that I personally know does this.

Again, I am not seeking specific instructions on this medication. But, I am hoping to understand whether this is truly necessary to endure on a monthly basis. Thank you!