I'm not going to get involved in the debate as such, but the reality is that the majority of visitors, and certainly the brits, use chalk in Font.
So if you do choose to use chalk, here's some guidelines:
Don't chalk up at the start of your session, just for shits. Use chalk as and when sweaty palms require it or
Just take a break, and stop lunging for the sloper like an epileptic. Rest and precision is a lot more useful than burning through skin until you sweat blood.
Don't use any more chalk than you need when you do use it.
If you've left excess chalk on the rock, brush it off.
If someone else has left excess chalk on the rock, brush it off.
Don't dab chalk directly onto the rock, or make tick marks of any kind. Learn to climb.
Be aware that any chalk left under overhangs won't get rained away - and locals might see it as graffiti. Clean it off.
Keep your chalk bag secure, and if you're sliding down a rock with a chalk bag on your bum, close it and move it out the way so it doesn't tip upside down.
Do up your chalk bucket between uses or
Don't take a chalk bucket since it encourages excessive use of chalk.
As a last thought, perhaps consider using liquid chalks since they seem to leave less chalk on the rock*
*and the fact that most of them are made with small amounts of pof mixed in doesn't matter so much in Font!