Open a US-domiciled USD account in your Kenyan company's name with Eversend. Clients pay you by ACH or wire like any American vendor. You hold the dollars, then convert to KES when the rate suits you. Receiving costs 0.49% plus a fixed fee, shown before the money moves.
Your client's transfer is domestic on their side, so there are no correspondent banks in the middle and nothing is deducted in transit. The amount they send is the amount that arrives, minus one visible fee.