I have had my MFLB now for about 3 years (I still use rubber bands around it!). While I brush it after each use, there is still a thick build up of gunk inside the trench. I have, in past, cleaned it with q tip and rubbing alcohol and gotten most of the stuff off with no problem. So several days ago, I used a q tip and rubbing alcohol to clean the trench, but only got tiny amount of gunk off and now I am having intense coughing each time I use it. I did try a water dampened q tip, but it did nothing to reduce what I am thinking is nasty alcohol fumes/vapor. This is very frustrating as I am a severe asthmatic and the coughing triggers bronchospasms. And the reason I vaporize is to keep my lungs from that type of stuff. Any way I can get rid of the nasty alcohol? I have used it now at least twice a day for several days, but no luck so far "burning" it off. I also tried with heating it with no herb in trench. I am even thinking of purchasing a new MFLB, if that is the only way to solve the problem, but I am on a fixed income and would rather not have the expense. By the way, I have used several strains of herb, so don't think the herbs are the issue. Thanks, and feedback is appreciated. By the way, is this something MFLB would replace the unit for?