diy waste ink pad almost full

So, I've had my canon i9100 for at least 3 years now, and I've been really happy with it, but just before Christmas I was getting error messages that the waste ink pad was almost full. When I looked this up online at canon.com they said to take it to a certified canon repair place. I called up two places and got over the phone estimates of about $100. The printer itself was about $300, so I opted to do it myself with the help of a few websites (thanks! to fixyourownprinter.com and tech guy forums). The most difficult thing was actually getting the top case off of the printer. After nearly taking apart my printer to what seemed like beyond ever being put back together again, I found that the "used ink tank" sponge was barely full. Evidently the error message is triggered by how many times you clean the printer heads or something. Anyway, I carefully took the sponge out and rinsed it in the kitchen sink with a little bit of soap until the water ran clear, I let the sponge dry on the radiator. Then I put it back together and re-set the code on the printer (again thanks for the fixyouronwprinter.com). And fingers crossed, did a test print and it seems like I saved myself about $100 and more to the point a pain in the ass cab ride with a huge printer sitting on my lap. DIY rules.