Cleaning unsealed old flags

[truelymadlysleepy]

My, soon to be, new house has very old flag stones in the sitting room. We're not going to change them even though they're not in great shape as it's listed.
They are really dirty & dusty. Would a steam cleaner work? I don't mind going something labour intensive as a one off but don't want to ruin them.
Any ideas?

I don't think steam cleaners are recommended on old stone floors... You have to consider the sub floor as well as the stone itself. I'd recommend a neutral detergent (fairy liquid is a pretty good bet) and plenty of hot water. If you've got a large area to cover, you could hire a floor buffer as a one off. And if they're really filthy, do it twice! After that, ecover do a floor cleaner designed for stone, ceramics and lino, which gives a nice sheen without loading it up with waxes.

Old fashioned scrubbing brush, Flash and rinse a lot with a damp cloth then when they are done, scrub them again.
When they are dry, Wickes do an excellent flag sealant.

Great advice.
The subfloor is just earth & the stones are not in the best state so scrubbing with a brush & bucket is sound advice.
Thank you.