Is is safe to drink alcohol from a reusable stainless steel flask?

yes it is safe to drink alcohol from a flask now and then put hot water and vinegar in it let it sit for a bit and then rinse out with hot water it will get rid of any bad taste of the flask th's how you clean them I boil my kettle and fill my flasks with hot water for my coffee's during the day saves reboiling the kettle and on power Hope this helps Luv granny M x