Snape's Greasy Hair... wizard tinfoil?

[Mark D. <uncmark@yahoo.com>]

No: HPFGUIDX 49265

I've gotten into arguments about wizarding attitudes towards beauty 
and haircare (Hermione used a wizard hair gel in GofF and Lockhart 
talked about hair care products) but still wondered about Snape. 

Almost all references refer to his hair as greasy and I have to 
wonder why a wizard as self-centered as Snape comes off as would 
allow his hair to be greasy.

I got a brainstorm while watching a scifi movie where a streetperson 
wore a tinfoil hat to 'keep aliens from reading his thoughts'. Could 
Snape's grease be a wizard equivalent?

Consider that Snape was a spy against Valdemort, who has 
demonstarated some degree of mindreading. How would Snape, a potions 
master, keep his thoughts private?  Suppose he brewed a potion that 
shielded a wizard's thoughts from Voldemort's mind-reading and 
possibly shielded from imperio. On the downside, it would make  your 
hair greasy, but Snape would at least keep his head.

As for why Snape still grases his hair, he knew Valdemort was not 
gone and still knew deatheaters were active.

Opinions? 
Uncmark