Anyone know how to remove silicone sealant from aluminium ?

I need to remove all the old mouldy sealant from my shower surround
and have used Unibond silicone eater to clean off the shower tray and
tiles but it explicitly states not to use it on aluminium. (probably
because it contains Sulphuric acid) The shower surround has aluminium
supports and they to have a bead of sealant down the whole length
which I need to remove.

thanks in advance...
Andy