Is this a good idea or am I stupid?

I have inherited some oil stones can they be used to hone straight?

Telling us what type of stones they are or some pics may help us help you :)

Well it's very smooth and you add oil to it I think it says carbide on the wooden case

That could be for sharpening carbide chisels or any number of things...that doesn't help much

Normally oil stones are thought of as being coarser than even the coarsest stones used to hone razors.
You could use a fine oilstone to hone away metal from a blade that needs work to remove chips and for major reshaping.
A coarse stone tends to leave larger micro chipping than a finer one, so its use should be linited.

Does it say anything before carbide?

Can you post pics? Measurements?

At best it's a fine old Arkansas stone. If its a courser, man made stone then there are better options.

Michael

I would be hesitant to use them. Because most carbide stones are made for rough work, and they would eat up your edge and leave a lot of micro chipping. A pic would be helpful. Your safest best would be to try it with a dud razor and see what happens.