As a smale scale commercial processor myself can I ask who on earth suggested you rinse and dry them

It is almost impossible to rinse out pour ons.........they are rain proof and designed to stay active on wet sheep
However if last years fleeces the pour ons will be fairly harmless by now........unless organo phosphate dips.
If you have 100 fleeces you will have enough to send to a large commercial scourer like Chadwicks in Bradford who will wash anything!!! (minimum amount 250kg)
I reccommend you sort this out with the processor as what you have been told to do is impractical and daft! You could well ruin the fleeces which have to be washed and dried quickly or they rot if left wet!..........and spinning out the water and drying that quantity of fleeceby hand is.....well......difficult. Do NOT use your washing machine or they will be ruined!
If we can help let me know, we have a small commercial scourer which we are taking bookings for and whilst I very rarely promote my business openly on here I think you may need some help!