Friend, fipronil has a wide safety margin in dogs. fact this is the active ingredient used in Frontline. The roach bait generally is much less. Generally when ingested symptoms are very mild like vomiting. I don't believe this will be life threatening for Max. I would keep an eye on him, if he develops vomiting or diarrhea this is what you can do:
1- Do not give things like Pepto Bismol or imodium. Start him on Pepcid AC (famotidine) 10mg 1/2 tablet every 12 hours for the next 2-3 days. You can buy Pepcid AC over the counter in any pharmacy.
2- No food or water for 4-6 hours. Need to give his gastrointestinal tract time to rest. Keep him indoors when fasting in a cool room and no exercise.
3- After 4-6 hours offer a small amount of water. Wait half hour, if no vomiting, offer small amount of rice (50%) and boiled boneless chicken or ground beef (50%) 4-6 times a day. Keep on this diet for several days then wean into regular diet.
4- If he continues to vomit after doing the above he would need to be seen by your family veterinarian for a hands on examination.
My goal is to provide you with excellent service - I hope I've provided the information you were seeking, if you feel you have received anything less, please reply back as I am happy to address follow-up questions. Kindly rate me when you are done.