I would suggest using the Tag property of the controls you want to clear. In the subform set the Tag property to 1 for all the controls you want to clear. Then use a For Each loop to clear only those controls where the Tag is 1.
Here is some code:
Dim varControl As Variant
For Each varControl In Me.Subform.Form.Controls
If varControl.ControlType = acTextBox Or varControl.ControlType = acLabel Then
If varControl.Tag=1 Then
varControl = ""
I added a check to see if the control was a textbox or label. This may or may not apply to you.