I would still say get the work experience! The job may not relate to accounting, but it relates to working. While I was in college, I scrubbed dishes in a cafeteria and rang up groceries in a store…neither one has anything to do with accounting, but they demonstrated that I could and was willing to work, show up on time, not steal from employers, etc., all of which helped me to get to eventually working in accounting. I went from the grocery store to a bank, then graduated while at the bank, and then got a job for an accountant who used to be a banker. If I hadn't worked at the grocery store as a cashier, I wouldn't have been able to work at the bank as a teller…and if I hadn't worked anywhere at all, I don't think my accounting-boss would've given me a second look.
But like JMadsen said, still keep your eyes open for other opportunities. Perhaps ask your friend how long of a commitment he's looking for…like, if you promise to give it your all while you're at the store, is that sufficient, or (due to your friendship) is he expecting you to stay at least a certain length of time? As an associate in retail, the company is lucky if you stay a few months, let alone anything longer! So, if it weren't for the friend-commitment, I'd say to not worry one bit about leaving after a short time if an accounting position opened up. However, given that the store is run by a friend of yours, you might just tell him that honestly, your goal is to work in accounting, and if a position came up to do so, you'd have to take it…but that if that's OK with him, you'd like to still come to work for awhile.
Assuming he's OK/your friendship is OK with the possibility that your time at Home Depot would be short, I would say take the job and make the most of it. Work is a good break from studying, and studying a good break from work. I am working close to full-time (34-40 hours depending on the week) and aim to complete my exams in the same length of time as you are aiming for…so working 25 hours you should definitely be able to keep on target for your exams. Like I laid out in my last post, you still will have plenty of time to study and do the incidental stuff in life. You won't have a full 2 days off for a weekend every week…but that comes with the territory. If you took a poll of the members of this forum, only a very very small minority would have 2 days work and study-free every week, and a large number wouldn't even have one. Completing this exam requires making sacrifices, but work experience is *not* something I would sacrifice.