CIP and de-ionized water requirements causing a large headache for something I don't think is needed. What do you think?

Hello, we are building an medical marijuana extraction lab that will become GMP compliant. In this process, though, I’m hitting a bunch of small issues that keep driving costs up. In this instance, we are being told we need to install a reverse-osmosis water system for the final rinse on our CIP. That system is being quoted as costing US$70k to have 150L of de-ionized H2O available every week or two for a final rinse. The thing is, I run an ethanol extraction system. The final rinse of RO H20 is to ensure no microbial contamination.

Can I just run plain ethanol through as a final rinse? I have lots of that, and it’s a heck of a lot cheaper than building this system. Even cheaper by the L than purchasing RO H20 in small amounts from a 3rd party.

I’m being told by consultants here it is 100% required for GMP to rinse with RO water. But I think I can show no contamination and more if I flush with pharma grade 95% ethanol.

Thoughts or experiences to share? Thank you!