I've tried foil, and it was a pain to shape it into place. I ultimately scrapped it.
The process I've developed is once I've ground all the coffee I want to, I pull the lid and use a small curved piece of plastic to scoop out any ground coffee remaining in the exit chute. Below is a picture of what I've adapted for this purpose... a plastic hair clip. I use one side on which I've cut off the hinge end using a Dremel tool. It's now a smooth curved piece of plastic that works as if it were designed for the purpose.
click here to see one...
http://www.missjkworld.com/pro_detail.php?ProId=293I then hold my hand flat and place it directly above the exit chute (think of how you hold your hand to your forehead like a visor) and pulse the grinder on and off (I've removed the timer board that came with my Tranquilo, and have a toggle switch in place of it... works great). This blasts out any remaining coffee from the burrs.
Next, I use a pastry brush I picked up at Target to brush out the exit chute.
After that, I use a foam paint brush to do a quick brush of the dosing funnel.
click below to see one...
http://www.jamestowndistributors.com/userportal/show_product.do?pid=1189&familyName=Foam+BrushesThis all sounds like a lot of work, but it is a snap and takes me about 10 seconds beyond the initial coffee grinding time.
One last trick that I use with my Tranquilo is that I grind directly into a very-small cocktail shaker that I got from Cost Plus World Market. I pulled the strainer out of the top part so that it can be inverted to dump ground coffee directly into a portafilter. An added benefit of this is that the grinds can be made clump-free with a little shake of the shaker - the WDT stir isn't needed.
Hmm, shaken, not stirred...