Lead foil will do a better job than aluminium foil. I recently heard from a fellow forumer that small lead tubes when encircling speaker cables at the speaker end improve the sound. Sounds crazy, isn't it
I haven't tried this personally so can't say how effective it is. But I'm perfectly willing to try lead foil when I have the chance to buy it from the market.
The usual caveat about lead being harmful applies.
PS: for the record, I'm a happy camper in the Mogami camp. I use two pairs of Mogami 2803 and Mogami 3103 speaker cables. Earlier I had used Mogami
2954 ICs till they were superseded by the 2803s.