George Clooney wishes he'd bought stock in Flowbee before endorsing the hair-cutting tool.

The 59-year-old Hollywood star revealed last month that he cuts his own hair using the electrically powered vacuum cleaner attachment.

Since then, the Flowbee has flew off the shelves and sold out everywhere, and Clooney quipped that he should have got some shares in the firm before publicly commending the device.

He told SiriusXM Stars radio: “I should have gotten stock in that company before I told that story. I really screwed up on that one.

“So now I know: Next time I endorse something, I’m going to own some stock before I do.”

The filmmaker might be worth an estimated $500 million but he gets to save some cash by not making trips to the barbers and instead shears his own locks regularly because it's so "easy" to do with a Flowbee.

Speaking on 'CBS Sunday Morning', in November, he said: "I've been cutting my own hair for 25 years.

"Look, my hair's, like really like straw, you know? And it's so easy to cut. You can't really make too many mistakes. So years ago I bought a thing called a Flowbee, which when we were kids... It comes with a vacuum cleaner and the clippers? Yeah. I still have it. ... Listen, man, it works!"

However, the 'Midnight Sky' actor admitted he wouldn't trust his hairdressing skills enough to give his wife Amal, 42, a trim.

He added: "Now, I wouldn't do it to my wife …!"