Numerology has no place in Christianity. Please show us where Scripture says that scoffing at numerologists is wrong...
That said, I think Camping's interpretations are questionable. Here's why:
According to Camping, 23 means destruction, based on two scriptures (23,000 killed in one day as judgment; 2,300 days of misery mentioned in Daniel). Two scriptures seem tenuous for making this connection.
According to Camping, 17 means Heaven, based on connections with that number.
According to Camping, 10 means completeness.
According to Camping, 5 means atonment, based on .5 sheckles for sin offering.
3 means from God, God's will, etc.
Why do hese numbers apply to number of days from the flood? According to Camping, 5 x 10 x 17 x 5 x 10 x 17 = 722,500 days from the flood on May 21st, 4090 BC (according to our calendar).
Why was the flood in 4990 BC? Why is the earth 13,000 years old, as Mr. Camping believes? So you see, even WITH the numerology this kind of thing is rife with error.
Probability-wise, based on strength of correlation between the numbers and their associated conceptional meanings, and a semantical unpacking of them to mean days... I guess Camping's interpretation is as good as any other in its situation at a statistical spike in the probability domain.
It's best, though, to try to be ready in season and out of season, and to live every day as though it were our last.