Cage Liners for Eco Habitat?

[Black_Inky_Eyes]

So, this thread is for a friend as they recently asked me if they needed some kind of cage liner for their Large Living World Eco Habitat (they didn't want to join HC for only 1 question even after my high recommendation!) as the bottom is wood and I'm assuming can be chewed through or weakened by urine. I said they did and they wanted more info hence this thread. Anyway, I'm sorry if this thread isn't very factual this is just all the questions they asked of me:

" Are cage liners important for an Eco Habitat?
Are the liners specifically for an Eco Habitat safe?
What do you use?
Any recommended brands?

Btw do you know how often I should go without cleaning the cage?"

Thanks for any replies they shall be passed on and I'm sure will be highly appreciated.