I think they would work. If strength is an issue, may like to consider a small solid rod into it in the manufacturing process to reinforce it. I think laminated wood is pretty but wont be as strong as a durable as a solid piece due to the weather conditions and the laminate are glued. They can come apart quite suddenly.

I personally have a bike that had the handle lengthened by slotting in a pvc tube into it and a thicker one outside of it to make about 22mm. Its hidden in the grips and extends halfway through it. I didnt want to buy an additional riser as I have too many extra bikes. It rode without a problem. I believe that pvc would work was its slightly flexible and not easy to snap. If It isnt strong, i would slot in a copper tube to reinforce it.

I have a lot of hardware lying around so I try to use it to save some.

Check out these matching bamboo grips.