Have you worked out what it is yet? I'm a bit of a sucker for Tescos sushi and about 3 or 4 times a year I give in and buy some if I'm out and without lunch. This time as I sat in the car munching on my californian rolls I looked at the box and it screamed propagator to me!!!
The box was cleaned thoroughly and I folded a kitchen roll up into a 9th and popped it inside - perfect fit. I moistened the kitchen roll and sprinckled it with red cabbage sprouting seeds - and a few mustard seeds I had spilt from the packet and accidently mixed, at the weekend!!
Voila, perfect little propogator to get them started!
What have you managed to see in a new light and reuse????