Ether works better than alcohol because it dries 
so much faster.  But like Yann said you have to 
be extremely careful as not to erase the other 
lines.  Instead of a q-tip you can purchase 
cleaning swabs from an electronic repair store.  
They work better because they hold the solution 
better and they are lint free.  Also, wear rubber 
gloves to keep your hands from smearing 
anything.  If you are afraid to try this your 
self either practice on a crappy cel you don't 
like or get some transparency paper and make a 
fake cel to practice on.  Let us know if you are 
able to fix it.  Maybe anime-taro would let you 
return the cel. Good luck