Can you block out the jets on a jetted tub without permanently altering the tub?

Do not put any liquid in any whirlpool bath,ever. No oil, no soap,just plain water.

I know your problem. Add hot water to a level over the jets and turn the power on with no one in the tub.

It will clean itself. They get this way,unless it is frequently used.

You shouldn't do what you are asking as it will probably result in damaging the pump. Why not clean the pipes instead? There is a product called Whirl Out that will, when used properly, clean the offending gunk out of the pipes and keep it from returning.

I have personally used this product and it does work. I have attached a link to the product for you to look at. You can do a Google search to find where you can purchase it locally.

http://www.amazon.com/Summit-Brands-WO06N-WhirlOut...