Soda crystals & boiling water didn't work, what next?

[Floopy21]

Need to unblock my upstairs bath & sink drains. Any recommendations?

TIA!

There is some nasty stuff you get from the hardware store - in white bottle inside white box - sorry forget what it's called. IT WORKS but it is nasty.

Thanks for reminder as I need to get some for bathroom sink on way home from work.

bicarb, vinegar, then boiling water...the vinegar has a chemical reaction thingummy and acts like those scary chemical Mr Muscley things.

Brilliant, thanks. Will try Bucharest's method first as I already have all those things...if not, harsh nasty stuff it is!