Unless you have sludge your not going to see any visible debris in your filter at 750 miles.At step 2 when your running just new oil and clean filter for correct mileage for your paricular engine thats when liquified dirt-contaminants debris will drain off of parts and into filter. Now you will see what came out of your engine both in filter and in oil. You have a rinse cycle and thats why we say use dino oil. If you have a seal leak dino oil is a must as petrol chemistry of dino oil and chemistry of Auto-Rx work together to recondition seals and effect over miles stopping the leak. Synthetic oil is very expensive to use as a rinse and after Auto-Rx application is finished you can go right back to a full synthetic. Every Auto-Rx success post is based on one fact "Application Instructions " were followed. We are reformatting these instructions again on web site, Auto-Rx is a chemistry not a prepackaged one for all product and it works on ratio's. Auto-Rx works and we are trying our best to simplify how you can make it work for your vehicle.