Loctite products are very good but they are are also very expensive.
My local machine shops recommended similar, but much cheaper, products from Vortex.
I have found both the regular Vortex VT42 and the VT70 to be top class. Vortex comes come in either 10ml or 50ml bottles. You will be amazed how quickly it disappears, so I would advise buying the larger size.
{Regular use} Medium strength (blue): Vortex Nutlock & Seal VT42 (Loctite 243).
High strength (red): Vortex Studlock & Seal VT70 (Loctite 271).
For a local stockist contact Vortex on: 01642 713 613