Pete - I've tried the nail varnish technique and that works fine. It does tend to taste a little odd though, but the effect is so simiilar to Plasticover, I figured I'd just buy some of those instead.
Thomsax - I've also soaked them in alcohol. Which is very nice indeed. 🙂 - a teacher of mine used to keep his in a jar of whisky on top of his piano. This has two effects: they remain soaked and sterilised. However, some spirits have a 'stickyness' about them (Southern Comfort for eg) which is best avoided for the build up of gunk.
I've also drilled tiny holes in the heart (Similar to a brand from way back called "The Scientific" - which had a WAX heart) - Was ok, no significant difference.
I've cut tiny triangles out of the tip, to get a breathy sound.
I've rubbed the surface with the back of a spoon to flatten the fibres. That 'feels' good and tends to soften up the resistance making it a wee bit brighter.
Fibracells are fine. Bit pricey, but they do last. The sound is 'right there' when you need it, but the 'signature' sound is on the whole 'bright' (IMHO)- I know Bobby didn't like them, it's a personal taste thing. Also it's hard to find a strength that works for you as they are not graded the same as 'normal' reeds- soft / med soft/ med/ med hard/ hard... !?!?! whatever that means. Seems to have no direct comparison if you're used to a 2 half, say. Seeing as they tend to be a bit stiffer anyway. Oh, and the other thing about these is that after a good few months of playing, the top coating starts to peel off on the table. It's like a very thin layer of cellophane, which gives the reed a 'buzz' - but not in a pleasant way, can lead to squeeking. That's the point that you need to buy a new one.
I've also tried Bari Gold Star - fully transparent plastic. Again, a reed that has the sound 'right there' and consistent every time. Although that sound is LOUD and edgy. And they feel wierd under your lip.
One of the best tricks I picked up was from when I was researching Charlie Parker. It's not reported much, but as it came from a direct quote of his, I am inclined to believe it. He used to use tenor reeds on his alto. A trick he got from Lester Young, who told of how a lot of the tenor players used baritone reeds on the tenors. Now this involves quite a bit of shaving and carving to get it to fit correctly, but a bit of carpentry later and you have a fantastic - full-on - sound. Mind you, Parker used No 4 or 5 reeds and had the diaphragm of an elephant, so I wouldn't suggest going up a strength. But the principal stands, and it worked for me. But, like I said, I don't mess with them any more. I just like to "blow, and go"
It's a LOT OF FUN trying stuff out tho. 🙂