I have bouncy and squeaky floors. The floor joists are 2x10 on 16" centers and 16 feet long (about 50 years old, not sure of the type of wood, but in good condition). There are X cross-bridging mid-span. The subfloor is tongue and groove ~3/4"x3.3" (actual measurements). I have access to the underside of the floor in most of my house, but, there are wires, HVAC, pipes....that run under the floor joist. I have seen talk of ripping 3/4" plywood to the height of the joist and sistering in 2 layers, staggering the joints. My question here is: would a 1x10 by 8' board placed in a similar fashion be better? My logic (if flawed please advise!) is as follows:

Since plywood is made of sandwiched pieces of thin sheets of wood whose fibers run perpendicular to each other. And the sheets whose fibers run perpendicular to the floor joist (1/2 the thickness of the plywood) will essentially carry no weight. Would it be better to use 1x10 boards instead of plywood strips?

This would be a little more $ than ripping plywood, but if 2x strong, it would be worth the cost.

Second question. The floors are very squeaky. I cannot correct from above (hardwood floors) but thought I would use 1x1 pieces of wood (oak, for its strength/"hardness"?) and glue it into the corner of the floor joist and the subfloor. Then run screws into each subfloor plank and into the floor joist to tighten the subfloor to the joist. I would use something like Gorilla Glue that would expand a small amount to fill the existing cracks between the joist and subfloor (I plan to force it into the joint) before placing the 1x1.

Any input appreciated.