HOBC when blended with regular fuel will increase octane quite a bit, it will prevent knock in a high compression engine or an engine whose combustion chambers are carboned up. It will not clean anything at all.
If you want to clean the combustion chamber then you need a real solvent like caltex used to sell in Pakistan called CX3, later rebranded as techron.
If you have real bad buildup then you need to use something potent like General Motors combustion chamber cleaner - its pretty nasty. Naturally its expensive and everyone is not upto using it correctly and the parchoon/sabzi type spare parts sellers in Pakistan wont have it either. You can use some hot water trickled into the inlet manifold - the resulting steam it produces during compression stroke will remove a lot of the carbon from the combustion chamber (if any)
What you are thinking HOBC does is wrong - infact using HOBC blended fuel in an engine that does not require it will carbon up badly and if its clean - it will be like a dog's breakfast.