The only dishwasher detergent manufacturers that I know of (going back to the 1980s) were:
Lever Bros, who made "Sun" detergent,
Benckiser, who made "Finish",
and Procter & Gamble, who made "Freedom" - though I only ever saw this once, in a commercial wholesaler's.
Robert McBride of Manchester, typically made detergents for supermarkets, such as the Co-op.