How to remove leading spaces and/or "/" or "\" - excel

Question

I am new to VBA in Excel. I have a spreadsheet that always has 172 columns. A:FP. It may have 2 to many rows. For every cell in the spreadsheet, I want to remove all leading and trailing spaces along with any leading or trailing "/" or "\". A string can contain a back or forward slash, just not at the beginning or end of the string. My code removes leading and trailing blank spaces. It removes trailing back or forward slashes. However, it does not remove leading slashes. I cannot understand why. Is there a better way of accomplishing my goal? Thank you for your help.
For Each Rng In ActiveSheet.UsedRange
CellVal = Trim(Rng.Value)
LengT = Trim(Len(CellVal))
If CellVal <> "" Then
If Not Rng.HasFormula Then
While Trim(Left(CellVal, 1) = Chr(47)) Or Trim(Left(CellVal, 1) = Chr(92)) Or Trim(Right(CellVal, 1) = Chr(47)) Or Trim(Right(CellVal, 1) = Chr(92))
If Trim(Left(CellVal, 1) = Chr(47)) Or Trim(Left(CellVal, 1) = Chr(92)) Then
CellVal = Trim(Mid(CellVal, 2, LengT))
ElseIf Trim(Right(CellVal, 1) = Chr(47)) Or Trim(Right(CellVal, 1) = Chr(92)) Then
LengT = Len(CellVal)
CellVal = Trim(Left(CellVal, LengT - 1))
Rng.Value = CellVal
LengT = LengT - 1
End If
Wend
End If
End If
Next Rng

Answer 1

First, I'd say try to avoid UsedRange but find a way to get your last used row and column. Then, instead of making a ton of calls to the Worksheet object, I'd run over your values in memory through the use of an array.
Last, you can do many replacements etc. But maybe using a regular expression isn't out of place here. Just for inspirations, I'll put down the following:
Sub Test()
Dim ws As Worksheet: Set ws = ThisWorkbook.Worksheets("Sheet1")
Dim lr As Long, lc As Long, x As Long, y As Long
Dim arr As Variant
Dim RegEx As Object: Set RegEx = CreateObject("vbscript.regexp")
'Set up regular expression first
RegEx.Global = True
RegEx.Pattern = "^[ \/\\]*(.*?)[ \/\\]*$"
With ws
lr = .Cells(.Rows.Count, 1).End(xlUp).Row
lc = .Cells(1, .Columns.Count).End(xlToLeft).Column
arr = .Range(.Cells(1, 1), .Cells(lr, lc)).Value
For x = LBound(arr, 1) To UBound(arr, 1)
For y = LBound(arr, 2) To UBound(arr, 2)
If RegEx.Test(arr(x, y)) Then arr(x, y) = RegEx.Execute(arr(x, y))(0).submatches(0)
Next
Next
.Range(.Cells(1, 1), .Cells(lr, lc)).Value = arr
End With
End Sub
So in the end it's reading back the cleaned data to the worksheet.
Regex Demo