I saw this video on youtube on how to make a silent brass mute out of an air freshener, lol. I tried it and it suprisingly worked. I was very supprised since silent brass mutes cost about $80 and these cost about 2 or 3 bucks to make. All you need it a whole bunch of printing paper wadded up, super glue, a rezunit air freshener, and some weather stripping.
I was supprised that it worked for me, there is a bit more resistance, but it's every bit as soft and sounds the same (you'll need to drill a larger hole than the one on the video, or you'll have a lot of resistance to deal with). I had to really cut the weather stripping down with scissors (do that before you put it on, then you can do the final trimming after you have it on). I put mine a bit further up the mute than he did, and pulled the weather stripping tighter so that both ends met each other. You kind of have to really stuff it into your bell, try screwing it in rather than just a shove and make sure it's thin enough.
On a scale of 1 to 10 on difficulty to make, I'd give it a 3 or maybe even a 4, it's not that hard. I just thought I'd share it with you, it's a pretty cool idea when you're bored. I'm pretty impressed with the video myself, but I'm still glad I have the real silent brass, which I still prefer to use. I carry this rezunit mute in my case and my whole case smells like an air freshener. lol. I even washed them with soap and water before I assembled them and it still smells like an air freshener, which is fine. And when you blow, all the air goes out of the hole at the end and it REALLY smells like an air freshener. I have no idea who the guy who made this video is, but my youtube username is justshutuprightnow, which I don't know why I'm telling you this.
YouTube - How to make a trumpet mute out of a renuzit air freshener