I don't have a filter in mine and have not had a blocked jet in the past 15 years I have been using it. You need to think about why yours is blocking.
The jets may block is if you have scale in your cleaning system that is finding its way through , or detergent buildup or cleaning powders that are not mixed properly or contamination in your clean tank. Check all these out and flush your system through.
There is no reason why you can't fit a filter yourself. They are available from most suppliers.
It is more likely to block if you are using an 01 jet. You could try using a large size e.g., 02,03, OR 04. They are also available from Amtech. I use all 4 depending on what I am cleaning.