AT YOUR OWN RISK....
I have found that filling the capping station with Acetone is a sure-fire way of dissolving any dried up ink that is clogging the waste lines, but DO NOT let it sit in there more than a few minutes. And, flush it out with several cleanings and them empty the waste tank. The Acetone will turn certain things into jelly. So far, it has not done any damage to mine, only helped it a lot.
I have found that filling the capping station with Acetone is a sure-fire way of dissolving any dried up ink that is clogging the waste lines, but DO NOT let it sit in there more than a few minutes. And, flush it out with several cleanings and them empty the waste tank. The Acetone will turn certain things into jelly. So far, it has not done any damage to mine, only helped it a lot.