Skinflint co-worker of mine was talking about the $$$ he was saving this summer instead of buying filters for his central air, he was taping strands of paper towel to his return grill and pulling it tight as to not be sucked into the unit.
He said he changes them every 3 weeks during the cooling season and every 2 months during the heating season, and has no issues (that he knows of).
I asked if he thought the lint from the towels might be problem, and he countered w/can't be as bad as the dust let through by many fiberglass filters.
I tempted to not forward any suggestions to him from the experts and let him to his own peril, but being the good Samaritan I am......
Thank you (I think)