If the money is not used for other needs such as mobilization costs and other needs required for the company, he can invest the money in Bitcoin.
I agree with you. If that money is idle at the bank (losing purchasing power to the inflation) without any purposes of being used soon, why not invest in Bitcoin, then? That sounds a logical idea for me.
However, before going too far, you must first give him an understanding that Bitcoin is not always profitable, the Bitcoin market which continues to fluctuate can cause the value of the asset to decrease when the Bitcoin price is traded below the price he invested. This literacy really needs to be done so that he doesn't blame you when the value of his assets continues to decrease.
Yes, he needs to explain his friend the basic concepts of Bitcoin, and what he should expect from this investment on short and long term. From that moment on, his friend can also start searching for informations and knowledge by himself, as there is a lot of content on the internet regards Bitcoin nowadays. He just have to make sure to absorb content from legit sources of informations.
Many Bitcoin adopters are fearful of introducing other people to crypto universe, but I guess to show them the tools, so they can do that by themselves isn't an issue at all...