Advice on work drug test

Hi I need some advice for my hubby. He suddenly has great job offer that we weren’t expecting and there is going to be a drug test, so had not prepared in advance to stop smoking. Is there any advice on what he can do (flush?)

It may be a few weeks away I’m not sure exactly when.

Advice please 🙏

(Also side comment, if marijuana is legalized for recreational use in our state should companies be able to still drug test and discriminate? It’s not a safety related job. It’s finance. )