A true pipe pig? or a sponge? Could you post a link to the site or to the product.

I've used those on my rubber system with my line pump and even under LOW air pressure that thing could cause serious damage.  does it clean well? yes.  do i think it's worth the risk, especially considering the destruction it could cause in system 5 inches in diameter? no.  you be the judge.

Been using a rubber pig through different sizes and configurations of booms for years and it works well.Some booms require a little air to get the pig moving.NEVER through a hose.Stuff it in the boom,maybe a little grease or liquid soap,couple blow out cap,attach air line,if needed,then reverse,not constantly,a couple strokes,listen,couple more,sound pipe..........When pig is back,disconnect air line.LEAVE blow out cap on boom,fold it up.Actually a blow out cap with an air release valve is best.A very small amount of build-up in the pipe will stop a pig,a wet sponge ball behind the pig will cure this.Of course using a pig every day will prevent any build-up.Yes, there is a little more work involved,it might be worth it.I always prepare my pig,cap,and air line some time during the pour so if there is any problem,mostly faulty air lines,the problem can be fixed.MAKE sure there is NO AIR PRESSURE in the boom before opening up the back end for wash-out.ONE PSI can do alot of damage.NEVER BLOW OUT ANY SIZE FLEX HOSE WITH PIG AND AIR.Speak to supervisor before using any type of pig in boom.PLEASE,be careful,always.Some booms do not require air.

You can use a pig in the boom,but put a ball behind it ,because water/air will pass around the pig leaving it in an elbow.

Almost forgot" attach ball catcher to tip elbow.