physical means of weed control are temporary at best. think of it as mowing down weeds in the yard. if you don't mind doing it often and can stand the aftereffects of their presence, it will work, but it's not the best solution. also, bear in mind that some aquatic plants spread by rhizome like structures similar to bermuda grass, so breaking it up and mixing it around may just make the problem worse.
without knowing your particular situation, i would suggest you might look at the root cause of the problem. generally it's an unbalanced ecosystem. could be fertilizer run off from nearby lawn/field/pasture/cattle? too much sunlight? stagnation? too many fish or the wrong size fish? etc.
depending on the type of infestation you have. sometimes, its more complicated things that are harder to change, like depth of the the bottom of the pond, erosion raising the depth over time, etc. the only way to address that is with a complete draining and re-digging.
there are commercial herbicides available, but use with caution if you have fish, as lots of rapidly decomposing organic manner uses up available o2 and can cause a serious fish kill.
grass carp are a decent solution, but can take some time. they are also selective eaters, eating the things they like first and only then moving on to the less favorites. they may strip out the small numbers of good plants you have and leave the cat tails and duck weed for last worsening the imbalance problem.
also, don't forget that structure is good for fish, so having a balanced amount of growth is beneficial to 02 levels and hiding places for hatchlings and other invertebrates that are part of the food chain.
managing a pond envolves understanding a complex set of interacting forces. your local university extension office may be of some help in your local area.
amp