Have a go doing what I do;
2/3 Na (this can be solid or ASM or a mix, depends on what type of methanol I'm using )
1/3 K
It has worked really well for me, better than using just one or the other.
If the K is dissolved in the methanol first, so the methoxide gets quite warm, then any solid Na that is added dissolves quite quickly. Any ASM is added last and mixed well.