If you have a financial planner, they will likely agree that this is not the most favorable strategy for college funding, since educational loans have more promising features, such as low interest rates and tax-deductibility.
While various 401k Plan Administrators have different rules, typical 401k loan rules are outlined in the Fast Facts section.

Pros of 401k Loans

• Applying for a 401k loan is usually a very simple process.  Most times you can arrange for a loan simply by calling the plan administrator.
• Any interest you pay on the loan goes back to your account.  That is to say, you keep the interest you're required to pay on the loan.
• Interest rates are usually very competitive for 401k loans, even if you have poor credit.  After all, you're borrowing your own money, so that limits non-payment risk.

Cons of 401k Loans

• Perhaps the biggest drawback of a 401k loan is the fact some plans do not allow you to contribute to your 401k until the loan is completely repaid.  Check with your employer to see if matching contributions will continue if you take out a loan.
• The interest rate / expense paid on a 401k loan is not tax deductible.
• The term of the loans - five years / 60 months - is relatively short when compared to alternatives such as education, home equity and personal loans.

A good alternative to 401k loans is a home equity loan or line of credit.  The biggest benefit of a home equity loan is that the interest portion of the payment is usually tax deductible.