Van Straaten, who made the move from Leeds at the end of the 2002/03 season, opened his side's account in the second minute with a sweetly-struck penalty, but it was the home side that opened their try-scoring account first when former Northampton Saints hooker Chris Johnson burst over shortly before the 20-minute mark.
Titans fullback Jason Strange converted Johnson's try, but the home side could only watch as Sale wrestled the initiative away from them in the remainder of the first half, Van Straaten adding a penalty before former New South Wales Waratahs flanker Stu Pinkerton crashed over for Sale's first try of the game just before the half-time break.
Van Straaten missed the tricky conversion, but he did add one more penalty in the half, leaving his side with a handy 14-7 half-time lead.
Second-half tries from right-wing Mark Cueto and inside centre Graeme Bond (eight minutes from full-time), both converted by Van Straaten, put the Sharks out of sight as they began to take full control, with the Titans unable to even make their way in enemy territory.
Rotherham eventually got on the scoreboard, again, when flanker James Cockle got over before the full-time whistle, Strange again converting, but it mattered little as the visitors had done the job already, perhaps ruing the missed bonus point, although four away points are better than none.
For Rotherham:Tries: Johnson, CockleCons: Strange 2
For Sale Sharks:Tries: Pinkerton, Cueto, BondCons: Van Straaten 2Pens: Van Straaten 3