There is only one way to repair wood rot
remove it completely and replace with something else, preferably more wood.
"miracle products" are just salesmen selling something to stop you doing what you should actually be doing.
example, you place the rot
doctor stuff over wood rot or you thin down and use epoxy
? well the rots still in there, if its not totally encapsulated and air tight, spores can still spread and rot will continue.
Just bite the bullet, cut out, dig out, use a chisel and poke out the rot until you get back to good dry wood and then repair it, you can still do it cheaply if you need to, the biggest cost will probably come from all the nasty hard to reach areas of your boat that rot has gotten in to which will need to be cut out to open up access.
alternative for smaller areas is to mix saw dust and wood chips with your resins for repairs
, at least then you have some wood fibers in the "glue" that you will be using to hold you boat together.