Can uneven ACQ treatment be corrected on decorative objects?
Fresh Alkaline Copper Quaternary(ACQ) treatment leaves the wood very wet.  In a month of dry conditions (in the sun), they will dry out and be much less splotchy.  The green will eventually be gone, going to gray in 12-18 months.  

I know you didn't want to stain, but consider a light 'cedar' tone to even things out, until the green fades.

Once dry (3-5 weeks), you can stain for a more even color (water or oil based, )

Part of the unevenness comes from a mix of end grain (very absorptive), face grain and knots (non absorptive).  Pre-treatment of the end grain (usually at the top of turnings) with a sanding sealer (25% finish, 75% solvent) will help the stain finish evenly.