I created a work around as an Add-In. The following will clear the cache on the selected layer.
Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Linq
Imports System.Text
Imports ESRI.ArcGISExplorer
Imports ESRI.ArcGISExplorer.Application
Imports ESRI.ArcGISExplorer.Geometry
Imports ESRI.ArcGISExplorer.Mapping
Imports ESRI.ArcGISExplorer.Data
Imports ESRI.ArcGISExplorer.Threading
Public Class CacheButton
Inherits ESRI.ArcGISExplorer.Application.Button
Public Overrides Sub OnClick()
Dim xlayer As Layer = TryCast(ESRI.ArcGISExplorer.Application.Application.SelectedItems(0), Layer)
xlayer.ClearCache()
System.Windows.Forms.MessageBox.Show("The cache for the selected layer has been cleared!", "Layer Cache", Windows.Forms.MessageBoxButtons.OK)
End Sub
End Class