I guess I will be a nay sayer on both chemical methods mentioned here - lye and potassium dichromate. I'm not commenting on the UV exposure or milk paint ideas.
I just don't understand how such caustic (both) and carcinogenic (potassium dichromate) materials would be advised for household or shop usage. Yes, I know that 'oven cleaner' is lye, and that lye COULD BE disposed of and (diluted to the extreme) in a waste water system - IN SMALL QUANTITIES. I am not advising or condoning that in any way.
But potassium dichromate is a carcinogen, mutagen, and has reproductive toxicity. Even in industry (with appropriate usage precautions) usage of this is being phased out (at least in my experience in industry, that may not be true as a blanket statement). There are many concerning sections of the publicly available Safety Data Sheet (SDS). I have attached the one I found from Fisher Chemicals. Please read through that - twice if you can - to understand the real risks of using such a material.
I actually hesitate to post such things - I am not trying to fear monger or be alarmist. I am willing to raise cautions with chemical usage like this. Both the usage risk and disposal issues are such that I hope you do not go this route, especially when there are much better options.
I have a great oil based cherry stain that I have used successfully. Want to try it out? I have most of quart left. DM me.