JuMP/cplex: setting array of variables to zero (in one shot), in heuristic callback

Dear community,
I use JuMP 0.18.5 together with CPLEX 0.4.4 and want to set new solution values in a heuristic callback. I have a quite nasty array of variables

x[w,i,t] ∈ {0,1} ∀ w ∈ {1,2,…,19,20}, i ∈ {1,2,…,74,75}, t ∈ {…} s.t. !(iszero(TLmax[w, i]))

where most values are zero.
Is there a way to set all of them to zero ideally in one shot without iterating over all values?

Thank you in advance,
best, michael.