Slot 1 : AIR (Alternate runes if needed : BODY 26 or CHAOS 21).
Slot 2 : COSMIC(1), COSMIC(2) or NATURE (Alternate runes : SOUL 28 instead of cosmic(1); DUST 22 or SOUL 20 instead of cosmic(2); WATER 29 or MIND 18
Wednesday's vis wax combination for the "Rune Goldberg Machine" is:
1st. Slot: BLOOD rune (replace with ASTRAL rune for 27/30)
2nd. Slot: Option A: AIR rune (cheap enough so no replacement needed)
2nd. Slot: Option B: CHAOS rune (cheap enough so no replacement needed)
2nd. Slot: Option C: SMOKE rune (replace with MIND rune for 29/30)
3rd. Slot: random rune for every player
you may also go to runescape.wikia and look up "Rune_Goldberg_Machine" for the true cost of each rune