Credit Repair Companies

I learned about a credit repair company from my brother who used them to remove inquiries and deliquent accounts from his credit report in order to raise his score and get a better loan rate for a mortage loan. According to him it worked and only took about 6 months to start seeing improvements on his credit. We live in louisiana and is that really possible? I don't have alot of debt, just old credit cards like Premier, Ochard and cards that don't give out high limits anyway. Should I use this service my credit score the last time I checked was 445. I need to get my credit straight. Any help will be accepted.