Regardless of what you do, you'll need to find out what condition the drive is in. Obviously, you can just try the (expensive) enclosure and see if it works, but if there is an Apple Store that's convenient to visit, I would call Apple and see if the Genius Bar can transfer the files without a cost to you (I'm pretty sure they'd be able to do a check of the SSD for free). An appointment to the Genius Bar may not be immediate, though.
If an Apple Store is not convenient, you might want to try an Apple-authorized service provider. They will almost certain charge for checking out the drive and transferring the data but it might be cheaper than the enclosure.
Even if it appears to work, the Apple Store or the Apple-authorized service provider should be able to do additional tests of the SSD to see if there was any issue that arose from the spill.
You'll also need to consider what you want to do with the SSD after (if) you get the data. These drives (if it works) command a good price in the used marketplace because Apple used a proprietary connector so people just can't go out and plug-and-play a non-Apple SSD. You can only use these drives in certain Macs (not the newest MBP's) so that needs to be considered if you're thinking about using it in another Mac. If you want to use it as an external drive, then perhaps the cost of the enclosure would be worthwhile. If you have a Windows (or Linux) computer with what's called a M.2 PCIe connector, there's at least one company that has an adapter that will allow your drive to be used there.
If you find a used, replacement MBP of the same model and year that had the opposite problem - the computer works but the SSD is missing or doesn't work, that's a possible solution.
