What's the significance?

The cedar-wood signified the restoring of the leper to his strength and soundness. The scarlet wool signified his recovering a florid color again, for the leprosy made him white as snow. And the hyssop intimated the removing of the disagreeable scent which commonly attended the leprosy.

The burning of the red heifer has a couple distinctions from other sacrifices offered. First, a red heifer was far more rare than other colors.   Second, the sacrifice took place outside of town, rather than in the temple.  Third, this heifer was to be provided at the expense of the congregation, because they were all to have a joint interest in it; it would serve to purify them all.  Jewish history says that the first red heifer provided enough ashes to last the Jewish people nearly 1000 years – others later only lasted several hundred.  All those who were involved in the sacrifice became unclean for a period of time.

If you think about it ... Christ’s sacrifice was distinct from others (animal) .  He was the rarest of sacrifices.  The crucifixion took place outside of town.  All would be purified by the sacrifice.  It would be sufficient to last.  All those who participated in the sacrifice were guilty.  Just sayin’.