want to use the local sandstone

I am putting in a pool deck in Thailand and want to use the local sandstone, which I assume would be similar to what is found elsewhere in SE Asia.  My question relates to what sort of impregnator would be appropriate for a salt water pool of this nature.  Does the application of an impregnator make sandstone tile more slippery when wet?  Is a sealer required for this kind of material and does that make footing more slippery?

Thanks, James

Could you please send me Maurizio's web site address as well?