Hi Laura! Check out this great information! Good luck!
Saltillo tile won’t shine as it’s unglazed. You can coat it being careful that it doesn’t become slippery. Coatings will build up dirt residue and have to be stripped. Not fun.
Laura to shine them you need to seal them. Betty has some great tips above.
You will be rewarded with your prepmand not skipping steps on the processs.