[TigerC10]

clean_gpc(array $source, string $varname, [integer $vartype = TYPE_NOCLEAN])

You're calling it like so:

[S]clean_gpc('p', 'venue', TYPE_STR)[/S] //bad call

'p' is a literal char, not an array. You should use it more like this...

clean_gpc($vbulletin, 'ProductOptionName', TYPE_STR)

//or

clean_gpc($vbulletin, 'Input', TYPE_STR)

But what you really need to consider is the addslashes function.

addslashes($input);

Much simpler, it'll automatically escape the quote characters...