Since first launching in 1995, more than 90 million gills have been sold worldwide, making it one of the best selling home appliances ever.
Foreman, who has expanded his endorsement empire to include, among other things, cleaning products and clothing lines, said he receives multiple requests for endorsements every week and claimed he is not motivated by money.
He revealed to Campaign that the key to successful product endorsement is to "latch on to something that people will fall in love with".
"To show someone the importance of the grill and how to use it, it's not really selling, it's like enforcing the great influence on their life.
"When you go out and try to make a lot of money the marketing would be no good. People can see right through it. But when you have a good product and you really believe in it and you know people can be helped, that sells it and it sells you too."
Foreman said that his experiences in the boxing ring and the challenge of selling himself as a future champion had prepared him well for a career in product endorsement.
"You know I'm having a lot of fun selling. I get offers day in day out and I have to say no to a lot of things.
"The hardest thing was having to sell myself as the next heavyweight champion of the world boxing teaches you how to sell. A lot of people thought I was just playing.
"Then at the age of 45 I become the oldest man ever to do so. Now people take note that 'maybe he knows what he's talking about'.
He went on to say that he believed not enough of his fellow sports stars were aware of the benefits of celebrity endorsement and said they have failed to launch long-term successful campaigns.
"I think that all athletes should be out there a little bit more. And I've set the stage for them now. I think that what happens is you get to be known worldwide for a long time and then you fade off the scene and somebody else takes your place."
Foreman hopes to boost the brand across the Middle East.
"I think this will change the whole Middle East, the George Foreman grill. Everyone will have one. Then they'll see why I have so many."