I would add them to the compost heap. I doubt there is any flavour at all in them after 7 years.

Compost!

FataMorgana

you might be surprised at the aroma still left in the leaves. I make coffee, tea ,pads with my old mint, rosemary, thyme, lavender any herb will work. Cut either squares or circles out of material, 5 inches or so... sew two together, leaving a small hole and stuff the herb in them, not to tight,sew them up and then use to set a hot cuppa on. the aroma is relessed and it smells great. These make a great gift with some tea and a cup.

GeeMee2 - sledge hammers and nuts come to mind. That sounds like a lot of effort to salvage some 7 year old leaves of a plant which grows like a weed for most people. Still - if the OP has a lot of spare time it's an idea.

I waste my time making them for kids who are sick, elderly who are lonely, and vets who need a cheer... put them together with a couple of tea bags and sometimes a cookie or two. Get lots of smiles for the effort........

No offence was intended Gee Mee2 - but if the OP is going to that amount of effort I'd use fresher leaves. Mint is plentiful and cheap. The pads would perform better and last longer. I still maintain that the best place for herbs that old is the compost heap.

I placed some old mint in spots where birds and mice might find them to use as nesting material.

I had seen some sparrows making off with some of my growing tansy one year, which is what gave me the idea.