Not having kids nor having any issues with homeschooling... I'll chirp in and still voice a small opinion.
In high school (went to a private Lutheran school), starting freshman year we had the option of taking Latin (aimed at the males mainly to go on to ministry), and that was only time to join since it was 4 years of learning. I did not join at that time and have regrettedt it ever since. I struggled through 2 years of Spanish (sophmore and junior years), while seeing the Latin students whiz through with A's. I know I would have developed more of an understanding of languages and possibly retained more.
I did try doing tapes and books, and even simple conversations, in Kiswahili while I was married but never did grasp it. I do still have some Swahili in my head, which funny enough, gets mixed up with my Spanish! I have now decided that I will invest in Rosetta Stone if/when I would meet someone who speaks another tongue.