Yes but you must keep detailed records of this, as an audit from the CRA may be plausible. 

Please review the links below for more information before you start.

From the CRA - Incentives - https://bit.ly/2FnliDB

From the CRA - Gifts - https://bit.ly/2CtCzsX

From TurboTax Tips - Tax-Deductible Expenses for Commission Employees - https://turbotax.intuit.ca/tips/tax-deductible-expenses-for-commission-employees-5365