The real question should be why do you need to use fabric softener?
Most fabric softeners are toxic soup.
Personally I have never noticed a difference when the Ex used them. Our current household just uses a basic laundry detergent then drys the clothes. They all feel plenty "soft" to me / us.
It is unfortunate that mass comsumer markets have "bought into" a chemical dependency for these products...nationally this is a 700 million dollar a year industry with "dryer" sheets coming in at an additional 400 million.
I'll step off my soap box now and get back to your question...most liquid fabric softeners are not compatible with detergents that is why they are added during the rinse cycle...I would think that any residues would be clean with a few cycles of not using them. Give it a try...you may find that you don't need them...the cost savings and extra work saved would be a benefit.
Oh I found another great article
Do you have a front load washer, or a top loader? Do you see residue on the drum, or is there some other reason you believe you have a fabric softener buildup? If you see an actual buildup on the drum, I would think wiping it with white vinegar would cut the film. Wiping the drum with a Mr. Clean Magic Sponge (or Walmart's version) would possibly do it too. It's amazing the various types of grunge those little sponges will clean! Now if you are noticing any foul odor, like a mildew/mold smell in your washer or clothes, and think it's a softener buildup, that is actually a whole other (more complex) issue.
After you remove this film, and if you still want to use your softener try diluting it a bit more with water before adding to the machine.
Then I changed the incoming water to warm and then I add the dirty clothes.
I use vinegar , it works really well .just add to the spot marked for bleach . And it leaves everything nice and soft .
Just a thought but if it is clogging up your washing machine, think what it is doing to the environment and waterways? What price soft clothes?
I dont like fabric softeners, I use white vinegar to reduce static and to remove the leftover suds from my clothes....cleans the washer as well, added bonus. :)