Asking your guests to bring their own condiments (salt, pepper, ketchup, etc.) to your BBQ is another option. Everyone has the same mindset and will not be offended.
Hiring us to man your buffet stations, butler food and serve drinks is also another way to lessen cross contamination (It is also the BEST method:)
Another option is to hire a food truck service for your main food and have us handle your other side dishes and drink stations.
Most importantly, get a tent and make sure you have ample space for seating!
Place hand sanitizer at each table and around the premise.
Paper towels and Lysol wipes in the bathroom are also recommended. For bigger parties, consider renting an upscale Porta Potty.