misterzippo --- all these coolerdors, tupperdoors, etc. are nothing more than a cheap alternative to the genuine humidor. They are used mainly for overstock, not as a primary humidor.
Sure, you can store your cigars in just about anything ... but it's not going to be a humidor. The Spanish Cedar is used for a reason ...
... so if you want to do it right, then fork out the cash for the wood ... heck, you spend top $$$ for your cigars ... why store them in a substandard home?
Since you are going to all the trouble to retrofit something that wasn't meant to be a humidor in the first place ... why not at least give it the cedar lining to make it 'somewhat' into what a humidor was designed to accomplish?
The cedar lining has a purpose ... use it!