Many of us who have sharp corners suffer from rail squeal around the corner. I always thought it was flanges rubbing on the rail which made the noise. It may contribute to it but its not the only factor.
Quite early on in our railway we learnt that a bogie or wagon tends to crab on the corners. The leading axle pushes against the outer rail, while the rear axle pushes against the inner rail. We noted that by following the practise of slightly opening the gauge lead to the increased crabbing and in turn angling the leading flange towards the rail and increasing wear of the softer aluminium rail.

So how do we stop it?

Greasing the rail? - works but the knock on effect of lack of adhesion is often a much more serious problem then the noise.
Water? - Well if the noise is really getting to you , a quick watering with a watering can, can help for a short period. This has or is used in at least one location on Network Rail.

The Ultimate Solution
Independent wheels – i.e. the outer wheels can turn independently from the inner ones.

Why haven’t we done it? The fixed axle with a bearing at each end is robust, simple, keeps to gauge and cheap.
The moment you separate the wheels you have to provide the means of keeping each wheel in gauge – stop a wheel moving in or out. – I am going to have a play but until then keep watering. – Paul